GLOBAL SYSTEMS EXAM

What is the biosphere?

All living things including plants, animals, and microorangisms

What is the atmosphere

All layers of gas surrounding the earth

• nitrogen

• oxygen

• carbon dioxide

• water vapour

What is the hydrosphere

All water on earth

• oceans

• lakes

• rivers

• glaciers

• groundwater

What is the lithosphere

All solid outer layer

• rocks

• mountains

• soil

• tectonic plates

What are all the ways that the sphere’s interact naturally?

volcanoes, earthquakes, floods, bushfires, rain, erosion

What are human influences cause sphere’s to interact with eachother

deforestation, pollution, agriculture, and urban development

What are all the steps of the water cycle?

Precipitation → surface flow → groundwater flow → evaporation → transpiration → condensation

What are all the steps of the carbon cycle

• Carbon dioxide in the air

• Photosynthesis – plants take in CO₂

• Animals eat plants – carbon moves through food chain

• Respiration – plants & animals release CO₂

• Decomposition – dead things break down, releasing CO₂

• Fossil fuel formation – dead matter becomes coal/oil over time

• Combustion – burning fuels releases CO₂

What is the photosynthesis equation?

6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂

What is the respiration equation?

C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O

Influences that affect the spheres and cycles

Volcanic eruptions, wildfires, Lightning, Ocean currents

Human induced influences on the spheres and cycles

Fossil fuels, deforestation, Agricultural, urbanization

Nitrogen cycle

Nitrogen Fixation → N2 becomes NH3 or NH4+

Nitrification - bacteria converts NH3 or NH4+ into NO2- then into NO3-

Assimilation - plants absorb NO3- and NH4+ through roots and use from to create amino acids, proteins, and nucleic acids

ammonification → decompoers break down dead plants and animals and release organic nitrogen into the soil NH4+

Denitification → bacteria converts NH2+ into N2 and back into the atmosphere

Lightning → N2 into NH3 so plants can absorb

Difference between weather and climate

Weather - short term, immediate state of the atmosphere, specific conditions like the temperature of said day

climate - long term, average weather conditions of a region or the entire planet, over a long period 30+ years

How can the sun’s energy and UV light energy be reflected or absorbed?

Ice and clouds reflect majority of the UV/visible energy back into space

Dark green forests and oceans absorb more of the light

What happens to the sun’s energy that is absorbed?

The energy is converted into heat energy and heats the Earth’s surface overtime

What happens to the sun’s energy that is reflected?

UV light that has been reflected becomes infrared radiaiton.

What happens to the infrared radiation once it reenters the atmosphere?

The radiation is absorbed by greenhouse gases such as water vapour, carbon dioxide, methane, ozone, and nitrous oxide

How does infrared radiation that reenters the atmosphere do to the earth?

Its keeps heat in the atmosphere warming the planet, leading to the natural greenhouse effect, essential for life, otherwise the earth would become too cold

What is the enchaned greenhouse effect?

The enchaned greenhouse effect occurs when humans added more greenhouse gases to the atmosphere, leading to more heat being trapped leading to climage change

What are the direct influences that humans have on the greenhouse effect?

The combustion of fossil fuels and deforestation leads to carbon dioxide being released, methane is released through mining, agriculture, and decomposition, nitrous oxide is produced in high temperature combustion (engines) and the use of fertilisers

What effect do human influences have on the natural greenhouse effect and the earth itself?

There is more trapped infrared radaition (heat) which leads to climate change (rising global temperature). This also leads to an increase in extreme weather events (droughts, floods, storms and bushfires), there is also evidence of melting ircecaps which lead to rising sea levels

Feedback loops that show how the enchanced greenhouse effect and quickly get beyond human control

melting ice caps. The less bright surfaces the less energy is relfected form the Earth leading to an increase in energy absorbed by the earth. Leading to warming, which in turns melts more ice, leading to more heat, more mleting and more heat. (this is positive feed back loop NOTE: positive = increasing which IS NOT good)

What is another exmaple of positive feedback loop that strengths the enchanced greenhouse effect?

Melting of permafrost. As the Earth gets warmer, frozen ground or permafrost begins to melt. The ground contains trapped methane and carbon dioxide, leading to these gases being released when the ground melts. Leading to more heat being trapped, leading to the Earth becoming warmer.

What evdience shows that humans are the cause of today’s climate change?

Past evdience of climate can be seen in ice cores (trapped ancient air bubbles showing part CO2 levels), tree rings (wider rings = warmer, wetter years), ocean sediments and fossils. Current evidence is rising global temperature, glacial retreat and ice melting, higher sea levels, increased atmospheric CO2 and more heatwaves, and droughts

How is wind created

When the Sun heats up the Earth unevenly leading to more heating of the land compared to the water, air above the land becomes less dense causing it to rise. Air above the water then moves to replace the missing air. This movement is what creates wind.

How do winds create waves

Through a process of energy transfer and friction. When the wind blows over the water surface it generates friction, which lead to a transfer of the wind’s momentum and energy to the water, leading to the formation of waves.

How are surface and deep ocean currents caused?

Surface currents are primarily driven by the wind and the Earth’s rotation. Deep ocean currents are caused by differences in the water density due to temperature and salinity variations

What are convection currents?

The circulation of water driven by differences in temperature and salinity. This circulation is a crucial factor in mixing ocean layers and sitributing heat and nutrients around the globe

What is an endothemic process?

An endothemic process is a chemical or physical process that absorbs heat from its surroudnings.

What is the exothermic process?

An exothermic process is a thermodynamic process that releases energy from the system to its surroundings

What do rising sea levels (melting of ice caps) lead to?

increased coastal flooding, erosion, and saltwater intrusion into freshwater sources.

How do rising sea levels affect the global current system

can alter the ocean's salinity and density, impacting the circulation patterns that drive the currents